LTM4677 datasheet(18/110 Pages) AD

18 / 110 page

LTC3888-1

Rev. 0

For more information www.analog.com

OPERATION

OVERVIEW

The LTC3888-1 is a constant frequency analog current

mode controller for DC/DC step-down switch-mode appli-

cations. It provides up to two independent voltage loops

(masters) and also contains six additional slave modula-

tors, affording a wide range of predetermined PolyPhase

configurations.

The device is designed to be used with external power

stages that provide an output current monitor, either as a

voltage or current. This includes higher level integrations

such as non-isolated power blocks. The LTC3888-1 pro-

vides a direct interface to the shared temperature and fault

indication bus commonly found on such power stages,

as well as an optional DrMOS gate drive supply voltage

supervisor.

The chip operates from a VIN power supply between 4.5V

and 28.5V. Without any other programming, output volt-

age may be set to any value between 0.4V and 3.45V

using an external resistor divider and the factory EEPROM

settings.

The LTC3888-1 also features a PMBus compliant digital

interface for monitoring and setting of important power

system parameters, including direct output control using

the external resistor divider, if desired.

About This Document

PMBus command pages 0 and 1 control the two volt-

age regulation loops associated with PWM0 and PWM1,

respectively. In this document, these may also be referred

to as masters or master channels. There are often unique

IC pins associated with each of these master channels,

such as ITH0 and ITH1. In cases where discussion applies

to both or either of the master channels, these pin names

may appear without index.

PWM2 to PWM7 are not directly controlled by PMBus

operation, but instead are managed by the master chan-

nel that is assigned to control them. In this document,

the modulators associated with PWM2 to PWM7 will be

referred to as slaves or slave channels. Occasionally the

term PWM or channel may apply to any of the eight PWM

modulators. Rail will designate a master channel and the

group of slaves it controls to produce a single output

voltage, including multiple master channels with wire-OR

ITH control.

The phrase operating memory or simply RAM refers to

volatile onboard RAM holding PMBus commands during

operation.

PMBus commands in this document are given in all

capital letters with no white space, although hyphens or

underscores may be included. For brevity, the indentify-

ing phrase PMBus command is most often omitted when

this typeface appears. All PMBus commands from 0x00

through 0xFF not listed in Table 7 are implicitly not

supported by the LTC3888-1. Writing to any command

not listed in this table may result in a CML fault and/or

undesired operation of the part.

MAJOR PRODUCT FEATURES

• Analog and/or Digitally Programmable Output Voltage

with UV/OV Supervisors

• Digitally Programmable Output Current Limit

• Digitally Programmable Input Voltage Supervisor

• Digitally Programmable Switching Frequency

• Digitally Programmable On and Off Delay Times

• Digitally Programmable Soft-Start/Stop

• Digitally Programmable Load Step Emulation

• Operating Condition Telemetry

• Phase-Locked Loop for Synchronous PolyPhase

Operation

• Non-Volatile Configuration Memory

• Optional External Configuration Resistors for Key

Operating Parameters

• Optional Time-Base Interconnect for Synchronization

Between Multiple Controllers

• Fault Event Data Logging

• Capable of Standalone Operation via EEPROM

Configuration

• PMBus Revision 1.2 Compliant Interface up to 400kHz

LTM4677 Datasheet(PDF) 18 Page - Analog Devices

LTM4677 Datasheet(HTML) 18 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL